After you have insert repository, go to first page of IM, click install. There you can choose which IBM software to install. As you can see in picture below I already have WAS, IBM HTTP and WEB Plug -in for WAS installed.

Select WAS and follow steps.

WAS is installed in /opt/IBM/WebSphere/AppServer.

6. Start WAS

After installation is finished, start WAS.

server1:~ # /etc/init.d/server1Node01_was.init start

Open web browser on you local machine.

https://IP_SERVER1:9043/ibm/console

Log in.

This is WAS administrative console. IBM call it Integrated Solutions Console(ISC).

In case that you can not get log in screen, check few things.
1.Iptables on server. Port 9043 is needed for Integrated Solutions Console. Once you connect to ISC, you can see what other port you need.
2. Check if your service is running